Crystal radio apparatus



Feb. 25, 1930. H. ADAMS ET AL 1,748,435 I I CRYSTAL RADIO APPARATUS vFiled March 12, 1926 2 Sheets-Sheet 1 I g IlaIIIIIhIHIIHIIHH||||llllllIIIHIIIH'HHIHIIlfimhllllhlllIHIIIIIHIIIIIIIHWFeb. 25, 1930. H. ADAMS ET AL CRYSTAL RADIO APPARATUS Filed March 12.1926 2 Sheets-Sheet 2 Patented Feb. I 25, 1930 uuirs} STATES seam ADAMSaw B- sen 0F wa ltl vsre DISTRICT or COLUMBIA onYsrA ammo APPARATUSApplication filed March 12, 1926. Serial No. 94,169.

Gun invention relates to improvements in crystal radio sets or apparatusand refers particularly to an apparatus of this char-I- aster which weare placing before the public under-the name or title,;lhe crystal dyn'eto distinguish our improvement in the trade and to guardagainstfraudulent imitations.

Que object of our inventioniis the provision of aradio apparatus whichwill have a it) much longer reception range or distance than sets inpresent use, we havingwcorered a dis I tance or more than one hundredmiles in a perfectly satisfactory manner as to clearness and volumeofsound. 1 1.5 Another object of our invention is the pro vision of a setor apparatus in which the finest adjustment of the cat Whisker ispossible and which will absolutely remain in proper con- 7 tactregardless of jar or hard usage. '2

vision of a radio set or apparatus which can be tuned with ease andfacility to suit condivtions and which will provide for thoroughprotection of all parts of the apparatus.

Another object of our invention is the provision of a set or apparatuswhich will be compact and small in size, which will be of" ornamentaland attractive appearance, which can be manufactured at the lowestpossible cost all things considered, and which in every respect will bethoroughly etficient and practical.

lVith the attainment of these objects in view, our invention consists ofa radio set or i apparatus embodying novel features of construction andarrangement of parts for service, substantially as described and claimedand'as shown in the accompanying drawings,

in which:

. ,Figure 1 represents a perspective view of a crystal radio set orapparatus constructed in accordance with and embodying our invention.

Figure 2 represents a top plan view of the apparatus.

Figure 3representsan end view. Figure 4 represents a bottom plan view.Figure 5 represents a sectional view taken 5.0 on the line 55 of Figure2.

Another'object of our invention is the pro Figure 6 represents asectional view taken on the line 6+6 of Figur 2.

Figures 7, 8 and '9 represent detail views of the crys al, holde andassoc ated pa t t more clearly show the details of this impor- 5;? tant'feat e o our invention, an

Figure 10 represents a detail view of the slider'rod, the slider, andthe tuning coil.

The casing is of the proper dimensions consists of the ai ed portion 1,which pre- 591 vides the tuning coil chamber 2, and the flat or tableportion .3, which is formed with the cavity or seat .4, said raisedportion being provided in its upper face with a $10 n which is mountedthe slid r od o gui i; upon which moves the slider 7 having theindicator 8, which travels over the indicating scale 9, and is providedwith the grasping or manipulating han le .10 and carri s he c1 1tact'll, which-engagesthe tu ing coil 12, said tuning .eoil being mouted 11 the in ulatin tube 13 retained in place by the sc ews 14:, whichalso serve as the fasten ng means fo the guide 6.

Connected at one end of h cas ng or 1? housing and assoeiated with thetuning ,coil is the binding post 15;, which provides the connection forthe aerial, while in the cavity 4, s mounted the in ula ing block 16, ofa pecial mate ial manufa tur d by u and 8 P ularly adap ed t r he pu poe, and in'th-is blockis mounted the phone o ne ing posltsl'i, and theground connection or post 18, the plate 18' being employed to makeconnection with the phones and ground and 3.5 through the medium of theterminal 19, connection with'the tuning coil is provided.

From this construction it will be observed that all the important partsof our set are is ofa special material possessing numerous Looadvantages and which is manufactured by us.

Surrounding the insulating block or case 23, is the rim or flange 27,which receives and retains the glass bulb or protecting tube 28, whichis further engaged and retained by the spring clip 29, and covers thecrystal as well as the curved post or member 30, which is mounted at itslower end 31 in the insulating block 23, and retained by the pair ofsecuring nuts 32. The curved or bail shaped post, it will be noted, isin a vertical position and retained thus and upon said post is placedthe conducting coil 33, whose free terminal34, forms the crystal contactor cats whisker of our invention. 7

The construction and arrangement of the crystal, the supporting post andthe spring coil with cats whisker forms one of the most mportantfeatures of our invention and it will be noted that the inherent springaction of the coil causes the contact or'cats whisker to bear positivelyand under allv conditions upon the crystal and in order to change'thelocation of contact it is simply necessary to turn or twistthe coil uponits support to bring the cats whisker-into contact with any desiredpoint or place'upon the face of the crystal, and under all conditionsthe contact is. assured between the cats whisker and the crystal, whilepermitting easy and ready removal of the coil with cats whiskerwhenfound necessary. I

The detector element or means ofour improvement is ofparamountimportance and consists of the crystal and the contact members,said contact member consisting of a rigid or stiif support and a springcoil which is entirely arranged around the support throughout its lengthto give columnar rigidity to the entire body of the coil and allow thecats whisker or free end of the coil to be adjustable and to bear underspring tension upon said crystal, this construction insuring the catswhisker bearing positively at all times in proper relation to thecrystal.

From the foregoing description taken in connection with the drawings,the operation of our set or apparatus will be readily under stood, suchoperation being so well known and established that elaboration thereofhere.

is not deemed necessary, but we claim particular advantage for the shapeand co nstruction of the casing, the arrangement of the tuning coil andassociated elements and also. for theconstruction of the crystal and thespring coil with contact or cats whisker, as these features combine toproduce a crys- 1. In radio apparatus, a detector element,

consisting of a crystal, a vertical support contiguous to said crystal,said support having parallel with the support, a contact member carriedby said support and comprising a lower terminal bearing against saidcrystal,

a coiled spring intermediate portion around sa d support, and a terminalwhich contacts I with said crystal, the coiled spring portionv holdingthe terminals in proper contact with thecrystal and allowing rotarymovement upon the support to permit the terminal to engage the crystalat difierent places.

2. In radio receiving apparatus, comprising a casing, a tuning coil, acontact and a crystal detector, said detector consisting of a crystal, avertical support contiguous to said crystal, said support having acurved upper portion at its upper end disposed parallel with thesupport, a contact member car ried by said support and comprising alower terminal bearing against said crystal-,.a coiled its a curvedportion at its upperend disposed

